Article of manufacture composed of gel

ABSTRACT

There are disclosed gels composed of hydrated phyllosilicates combined with a lattice expanding agent selected from the group consisting of a primary aminocarboxy acid, lysine orotate, and glycylglycine. Both organic and inorganic additions, as well as ion exchange products, are disclosed. The gels, with or without the additions, may be polymerized and may be formed or shaped. Also disclosed are methods for generating the gels and for treating the gels generated.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a division of Ser. No. 848,791, filed Apr. 7, 1986now U.S. Pat. No. 4,676,929, which, in turn, was a continuation-in-partof Ser. No. 742,954, filed June 10, 1985, now abandoned.

INTRODUCTION

This invention is concerned with useful gels generated from expandable,hydrated sheet silicates, also known as lattice layered silicates, orphyllosilicates. It is also concerned with articles of manufactureproduced by further treatment of such gels, and with methods ofgenerating and treating the gels. The silicate minerals of interestinclude vermiculite, beidellite, nontronite, volchonskoite, saponite,stevensite, sauconite, pimelite, bentonite, montmorillonite, hectorite,the smectites, attapulgite, sepiolite, phlogopite and biopyrobole; i.e.,in essence the entire genus of hydrated or hydratable phyllosilicateswhether of natural or synthetic origin.

The three layer micas in general, and natural vermiculite in particular,have been extensively studied because of their potential for thermalresistance and electrical insulation. The interest has heightenedconsiderably with the recent flight from asbestos products.

The term "vermiculite" refers to, and identifies, a specific mineralspecies. However, it is typical of, and may here be read as referringto, any hydratable, layer latticed, expandable silicate structure,primarily the three layer micas. The silicate layer units in theseminerals have a thickness of about 10 Angstrom (Å) units, with the mainelemental constituents being Mg, Al, Si, and O. These silicate layersare separated by an interlayer composed of water molecules associatedwith cations, such as Mg⁺⁺, Ca⁺⁺, Na⁺, K⁺, and H⁺.

In order to create a product from vermiculite, it is usually necessaryto delaminate the particles. This involves separating the crystals atthe interlayer to form high aspect ratio platelets. These may besuspended as a gel and subsequently deposited in any desired form, suchas a sheet, or otherwise processed.

At one time, it was standard practice to heat vermiculite particles toan elevated temperature. This caused the water-containing interlayer toexpand and pop open. Later, it was learned that vermiculite could beexpanded by reflux treatment with various salts in aqueous solution.Thereafter, application of an intense shearing force to the expandedparticles causes them to separate at the interlayer and form a gel.

It has been suggested that ion exchange takes place in the interlayerduring salt treatment. This may occur on standing for an extended time,but usually refluxing, or similar heat treatment, for several hours isprescribed.

RELATED LITERATURE

U.S. Pat. No. 3,325,340 (Walker et al.) describes a process forproducing an aqueous suspension of vermiculite flakes which comprisestreating crystals of vermiculite with a selected alkyl ammonium,lithium, lysine, or ornithine cation in an aqueous solution, immersingthe crystals in water to promote swelling normal to the main cleavageplane, and subjecting the swollen crystals to intense mechanicalshearing to form a stable suspension. Examples prescribe heating orrefluxing for several hours in the solution of cation salt followed byimmersion for a matter of hours to swell.

U.S. Pat. No. 3,434,917 (Kraus et al.) discloses a similar methodwherein vermiculite ore is successively exposed to sodium chloride andlithium chloride salt solutions, then immersed in water to swell, andfinally subjected to intense mechanical shearing to form platelets. Aspecific example prescribes steeping the ore in salt solution for 24hours.

United Kingdom Patent Specification Nos. 1,593,382 and 1,593,383disclose methods in which vermiculite is exposed to a salt of sodium,lithium, or an organo-substituted ammonium cation, followed by aqueoustreatment and intense shearing action. The suspension thus produced maybe washed, filtered, and then shaped against a mold as water is removed.

U.S. Pat. No. 4,305,992 (Langer et al.) discloses an intumescent sheetcomposed in part of unexpanded vermiculite flakes which have been ionexchanged with an ammonium ion. The patent also refers to severalpatents as showing thermal exfoliation of vermiculite.

U.S. Pat. No. 3,356,611 (Walker et al.) discloses treating vermiculiteto render it dispersible in an organic medium. The treatment is ionexchange with a substituted ammonium, phosphonium, or sulphonium cation,the substituent being a saturated or unsaturated aliphatic chain, apolyoxyethylene chain, and/or an aromatic or heterocyclic ring.

A publication by Isaac Barshad, in Soil Science Society Proceedings1952, pages 176-182 and entitled "Factors Affecting the InterlayerExpansion of Vermiculite and Montmorillonite with Organic Substances,"indicates that the determining factors are size, charge and total amountof the interlayer cations, magnitude of the dipole moment, and thedielectric constant of the immersion liquid. Alcohols, ketones, ethers,amino acids, and aromatics such as benzene were among the immersionliquids studied. There is no indication of gel formation.

PURPOSES OF THE INVENTION

A basic purpose is to provide a gel composed of a unique combination ofmaterials. Another purpose is to provide a stable gel that can be storedfor a period of time before usage.

A further purpose is to provide a gel that can be further treated,either physically or chemically, to provide a formable material.

A still further purpose is to provide a gel that can be flocculated byan ion exchange.

A further purpose is to provide a gel into which a further organic orinorganic material may be added to form a composite with the silicate.

A still further purpose is to provide a material having an organiccomponent and being resistance to deterioration at elevatedtemperatures.

Another purpose is to provide an organic-silicate composite that can bethermally polymerized.

A further purpose is to provide a simple, inexpensive method of rapidlydelaminating a layered silicate.

Another purpose is to provide a method for delaminating a layeredsilicate that is effective in a matter of minutes without application ofheat.

A further purpose is to provide a method for delaminating a layeredsilicate wherein the delaminating agent may be substantially recovered.

SUMMARY OF THE INVENTION

In furtherance of these purposes and others that will become apparentfrom the following description, the present invention comprehends a gelconsisting essentially of one or more of the primary aminocarboxy acidsand/or lysine orotate and/or glycylglycine combined with one or moredelaminated, hydrated or hydratable phyllosilicates, saidphyllosilicates being characterized in having a lattice or unit cellexpandable by a primary aminocarboxy acid, and/or by lysine orotate,and/or by glycylglycine, at least a portion of said primary aminocarboxyacid and/or lysine orotate and/or glycylglycine being intercalated inthe phyllosilicate. The cell expanding agent is most generally used in apolar liquid, most conveniently a water solution. However, it may alsobe employed in the dry state, if desired. The invention furthercomprehends shaped articles, such as molded bodies and films, producedfrom the gel.

The instant invention is also embodied in a method of producing a gelfrom a hydrated or hydratable phyllosilicate, said phyllosilicate beingcharacterized by a lattice or unit cell expandable through contact witha primary aminocarboxy acid and/or lysine orotate and/or glycylglycine,which comprises combining the phyllosilicate with at least one cellexpanding agent selected from the group of a primary aminocarboxy acid,lysine orotate, and glycylglycine to expand the lattice of the silicateand then separating the expanded silicate at the interlayer thereof. Theseparation is faciliated by applying a shearing force thereto.

Beta-alanine is the preferred primary aminocarboxy acid and can berecovered or recycled from polar liquid solutions through centrifugationor dialysis. The phyllosilicate of most interest is natural vermiculitewhich may be separated as a sheet or film, may be pressed or spraydried, may be subjected to dielectric drying, or may be flocculated forfurther processing.

In one preferred embodiment, a further inorganic or organic component isadded to the gel before separation. In the case of organics, this may bea polymerizable material which, in amounts up to about 20% of theproduct, permits producing a composite material having unusual thermalresistance.

GENERAL DESCRIPTION OF THE INVENTION

The present invention provides a gel which, in its simplest form, iscomposed of a selected, hydrated or hydratable phyllosilicate dispersedin an expanding agent which may be a primary aminocarboxy acid, orlysine orotate, or glycylglycine, either in dry form or in a polarliquid solution thereof. It further provides a quick and easy method ofproducing such a gel.

It is based on my discovery that, unlike prior expanding agentsemployed, the indicated agents will cause expandable layeredphyllosilicates to swell in a matter of minutes at ambient temperature,that is, without application of heat. It is further based on myobservations that not only the expanding agent, but also other materialspresent in the gel, may enter the lattice structure and becomeintercalated therein, that is, be held in the structure when thephyllosilicate is reconstituted.

The layered phyllosilicates may be synthetic, that is, reaction sinteredor melted and crystallized, or may be a natural raw material. Foreconomic reasons, the latter are usually preferred.

The phyllosilicates thus far found to be expandable by theabove-indicated agents include the natural hydrateable phyllosilicatematerials vermiculite, beidellite, nontronite, volchonskoite, saponite,stevensite, sauconite, pimelite, hectorite, bentonite, sodiummontmorillonite, sepiolite, phylogopite, biopyrobole and attapulgite. Inaddition to the corresponding synthetic materials, synthetic alkalineearth micas and polylithionites are also operative. The naturalmaterials are three layer, expanding lattice type phyllosilicatescharacterized by silicate layers separated by an interlayer containingH₂ O and metal cations (Mg⁺⁺, Ca⁺⁺, K⁺, Na⁺ and Fe⁺⁺⁺). The silicatelayer is actually composed of two tetrahedral layers, composedessentially of silica+ alumina, separated by an octahedral layer usuallycontaining Mg, Fe, Al, Li and OH or F ions.

It will be appreciated that mixtures of the expandable phyllosilicatesmay be employed in order to tailor certain properties. For example, achain-like structure such as sepiolite may be mixed with a plateletstructure such as vermiculite.

The effective expanding agents for present purposes are the primaryaminocarboxy acids, an aromatic modification known as lysine orotate,and a secondary amino derivative known as glycylglycine. Theaminocarboxy acids are characterized by an amino(--NH₂) group and acarboxy group (--COOH) separated by a primary alkyl chain composed ofmethylene groups. The lysine orotate is a modification involving anaromatic ring structure intermediate. N-glycylglycine is the simplest ofall peptide structures and is commonly used in the synthesis of muchmore elaborate polymeric structures.

Lattice or unit cell expansion proceeds very rapidly where the expandingagent is present in a polar liquid solution, such as water. Hence, theapplication of a low energy source of shearing action, for example, theforce of a food blender, will suffice to very quickly separate thesilicate platelets and form a gel. Consequently, in those situationswhere other factors are equal, an aqueous solution of a selected cellexpanding agent will customarily be employed.

It can be appreciated, however, that the inclusion of water or otherpolar liquid, will require the eventual removal of the liquid from thefinal product. The removal of the liquid adds another step in the streamof production, commonly a heating procedure to volatilize the liquid.Accordingly, it may be desirable to conduct the lattice expansion in anon-liquid environment. Where such is the case, the present inventioncontemplates the simple combination of dry expanding agent, i.e., atleast one of the above-designated expanding agents, with aphyllosilicate. A cell expansion from about 14 Å to about 20 Å or higherwill still occur in less than one hour under normal circumstances. Thiswill produce an anhydrous powder capable of being molded andsubsequently polymerized when heated with or without the addition ofother species, e.g., melamine, capable of being polymerized.

Quaternary ammonium silanes have been found to enhance the expandingfunction of the aminocarboxy acids. However, they were ineffective whenused alone, that is, in the absence of a primary aminocarboxy acid.

It is also possible to enhance the expansion function by using acombination or mixture of aminocarboxy acids. This may be observed as amore rapid expansion, particularly in materials such as sepiolite ormontmorillonite which tend to react slowly when a single acid is used.Likewise, when a mixture of acids is employed, subsequent polymerizationrates are enhanced, and the process may, in some instances, be observedat ambient temperature.

Whereas amino acids containing up to 12 methylene groups have proven tobe operable, short alkyl chain amino acids are preferred, both becausethey are less expensive and because they introduce less carbon andhydrogen, thus improving thermal resistance. The preferred acids have analkyl chain of 1-8 carbon atoms. Among these are glycine, beta-alanine,4-aminobutyric, 5-aminovaleric, 6-aminocaproic and 8-aminocaprylicacids. These acids may be used in combination with such long chain acidsas aminoundecanoic and aminododecanoic acids to permit condensationpolymerizations of polymers similar to nylon 6, 10, 11, etc. These acidsare also characterized as exhibiting high dipole moments. However, thisdoes not appear to be the sole reason for their effectiveness, sinceother materials with higher dipole moments have proven ineffective.

It is my belief that the effective aminocarboxy acids are capable ofrapid hydration-ion exchange in the interlayer of the silicate crystals.This exchange causes the lattice to swell or enlarge to an extent of atleast up to 20 Å which separates the silicate layers so that a minimalshearing force can delaminate them and generate the desired gel.

The currently preferred method consists of immersing about 10% by weightof vermiculite in an aqueous solution of beta-alanine that is about 3molar. The latter is selected because it is capable of subsequentpolymerization, cross-linking, poly-peptide, silanation, andco-polymerization processes, as well as serving as a precursor materialfor inorganic phase assemblages.

Prior to immersion of the silicate, the pH of the aqueous solution maybe adjusted as desired from acidic to basic or to the isoelectric point,6.0 in the case of beta-alanine. The silicate is then added and themixture agitated for a short time, commonly 2-5 minutes. The agitationmay be in a Waring blender, or other relatively low energy, shear-typemixer. This produces a fluid gel which may then be passed through a finescreen, e.g., 270 or 350 mesh, to remove coarse particles which arebelieved to originate from contaminants in the raw materials.

I have found that phyllosilicate gels, produced as herein described,will flocculate when dispersed in either distilled or tap water. Thefloc thus formed is excellent for wet screen paper making. Hand sheetsproduced in this manner demonstrated good strength and flexibility.

I have found that the gels of this invention will also flocculate whendispersed in a wide variety of solutions. These include the alkali metalchlorides, ammonium chloride, and chlorides of Ba, Mg, Ca, Cu, Fe andAl. Further, alkali or alkaline earth solutions of acetates, nitrates,phosphates, and hydroxides are also effective.

The largest and hardest floc particles are obtained by dispersing thegel into an aluminum chloride solution. When film or paper is made fromsuch floc and heated above 180° C., the chloride ion volatilizes as HCl,leaving vermiculite-containing, ion-exchanged aluminum. These aredurable materials with useful electrical properties.

In an alternative procedure, the flocculated gel is separated, rinsed toremove excess flocculating salt, and partially dried, if necessary,before shaping. Formed material or bodies may be produced by pressing,rolling, and injection or extrusion molding. Preferably, a small amountof a lubricating agent, such as stearic acid or methyl cellulose, isadded to facilitate shaping.

Where ion exchange occurs, as for example with AlCl₃ and with theseveral potassium salt solutions, it is believed Ca⁺⁺ ion can be removedunder acidic conditions and can remain in place under basic conditionsto form interesting inorganic phases such as Ca(PO₃)₂ or Mg(PO₃)₂ whenthe pottassium ion (K⁺) exchanges with the interlayer Ca⁺⁺ and Mg⁺⁺.Thus, when a vermiculite gel is dispersed into a water glass (K₂ O.SiO₂)solution, a reaction occurs and the reaction product can be formed intoa strong film or a hard cementitious article. Subsequent low-temperatureheat treatment may be expected to encase the potassium-mica in a glassymatrix of a soda lime glass nature, the interlayer magnesium and calciumions having been exchanged out of the mica.

It will be appreciated that a variety of low-cost fillers may beincorporated in the potassium mica-water glass material prior to thermalsetting. Such materials as fly ash, sand, calcite, feldspars, andnepheline syenite are contemplated. Once set and dried, the resultingbody may be decorated or coated in known manner.

An interesting photosensitive material may be produced by a silver ionexchange. Thus, a gel according to the invention may be poured into asilver ion-containg solution, for example, an aqueous solution of silvernitrate. The flocculated gel may then be dewatered on a screen and driedon a hot drum. When paper, produced in this manner, is exposed toultra-violet radiation and heated to about 480° C., a dark grey-blackcolored paper is obtained. Photosensitive darkening is also observedfrom exposure to a mercury arc lamp.

While flocculated materials, with or without ion exchange, are of greatinterest, one of the interesting attributes of the present gels is theirability to be used directly from the gel state. Thus, the gel, afterscreening to remove large contamination particles, may then becentrifuged to remove the bulk of the delaminating agent. This may be onthe order of 80% or even more. The concentrated gel may then bereslurried in water, or organic solvents, any desired additions made,and the material ratio adjusted, as by centrifuging, to satisysubsequent processing needs, the material solids content varying betweenabout 25% and 75%. The rheology of the material at this point can bemade to correspond to toothpaste. This is appropriate for extrusion,compression, or injection molding. The solids' content may be furtherreduced by organic or aqueous additions, thus adapting it to spraydrying or hot calendering to form sheets.

It will be appreciated that normal additions, such as fibers, fineparticulate material, and webs, may be made. Also, organic or inorganicspecies may be incorporated via solution chemistry.

After the material has been pressed, or otherwise molded, volatilesolvents may be removed in vacuum or by heating. The material may thenbe further heated to effect polymerization and cross linking of residualpolymeric species. Additional heating to temperatures ranging from 100°to 800° C. produces relatively more rigid materials. While many organicand inorganic materials may be added to impart unique properties, thewashed gels are capable of polymerization without further additions. Thelevel of residual organic is usually below 20% and can be lowered to˜0.5 weight percent via dialysis or centrifugation with only theresidual acid present.

The herein designated aminocarboxy acids, lysine orotate, andglycylglycine appear to be unique in their ability to quickly generate astable silicate gel from layered silicates. However, almost any organicor inorganic material of ionic nature may be employed as a secondaryexpansion agent. For example, secondary dipoles, including both carboxyand sulfoxy amino acids, may be employed. These include sarcosine, 3,5diaminobenzoic acid, m-aminobenzoic acid, p-aminohippuric acid,octadecylamine, taurine and sulfanilic acid. While these materialsfunction very slowly, or not at all, by themselves, they tend to augmentthe primary agents in expanding the lattice.

A wide range of other organic materials may be incorporated in the gelsto participate in such reactions as esterification, polymerization,cross-linking, silanation, and co-polymerization. The organic additivesmay be either aliphatic or aromatic in nature. For example, addition ofalcohols, such as methanol or glycerol, will lead to esterification ofthe carboxy acids. Likewise, carboxylic and dicarboxylic acids,aldehydes, silanes, silicones, and ketones may be added for reactivepurposes. Surfactants may be added if desired in further processingoperations, such as pressing, as may waste liquors from pulp making.

Where it is desired to produce a polymerized product of modifiedproperties, almost any polymerizable material or agent may beincorporated. These include melamine, guanidine, amides, diamides,tertiary and quaternary amines, aromatic amides, silanols, caprolactams,epoxides, phenolics, polyesters, polyvinyls, acrylates, methacrylates,acrylamides, polysulfones, stearates, citrates, acetates, cyanates,nitrates, carbonates, sulfates, borates, and acid and basic phosphates.

As a result, I have found it possible to produce polymerized materialshaving flame resistance. Thus, film and sheet materials that resistburning at temperatures up to 600° C., and even to 800° C. in someinstances, can be produced. Such heat- and flame-resistant materials areof interest in many areas. In particular, they hold considerablepotential for combustion engine parts.

In the area of inorganics, various acids, such as phosphoric, boric andhydrochloric, and bases, such as hydroxides of Na, K and Li, may bepresent. In addition, solutions of a wide variety of metal halides,including the alkali metal chlorides, chlorides of iron, chromium,cobalt, nickel, niobium and aluminum, and ammonium fluoride may beadded. As filler materials, such inorganic minerals as sand, talc,calcite, alumina, glasses, fly ash, zironcia, various sols of SiO₂, Al₂O₃, ZrO₂, and graphite, may be present as well as synthetic inorganicglasses, glass-ceramics, and ceramics.

It appears that once the lattice has been entered and expanded by anabove-designated expanding agent, the several other materials mentionedabove tend to follow into the unit cell and, because of their size, maycause further expansion. Various pieces of evidence indicate that thematerials position themselves between, and attach to, the silicatelayers. Thus, the process is one of intercalation of the organic and/orinorganic additives into the lattice or unit cell and between the silicalayers.

It is believed the enhanced thermal resistance of polymerized organicsis occasioned by such intercalation. Thus, the additives, and thepolymers that form therefrom, are found, in part at least, in thelattice where they are protected when the delaminated phyllosilicatereconstitutes. This can be of particular significance in the case oforganic dyes and colorants that tend to fatigue or destabilizeotherwise.

DESCRIPTION OF SPECIFIC EMBODIMENTS

The invention is further disclosed and illustrated with reference toseveral specific examples. In the examples containing a primaryaminocarboxy acid, the acid was generally a three molar (3M) or sixmolar (6M) aqueous solution unless otherwise indicated. The two carbonchain acid was usually preferred and is designated by its common name,beta-alanine. In all cases involving a solution of expanding agent,unless indicated otherwise, the layered silicate material and theexpanding agent solution were introduced at ambient temperature into adevice that imparted a low energy shear force for 2 to 5 minutes. Anordinary domestic or kitchen blender was customarily employed.

The silicate was examined, both before and after delamination to producea gel, by a low angle, x-ray diffraction (LAXRD) apparatus. Theequipment used was a standard Philips vertical powder diffractiongoniometer equipped with one-fourth degree divergence and receivingslits and a 0.1 degree scatter slit. The raw data were smoothed by adigital filter after fast fourier deconvolution.

Peaks in the curves generated indicated spacing in the lattice. Thus,changes in positioning and height of the peaks indicated changes inspacing in the lattice. Accordingly, for each gel produced, the twospacings observed are recorded, the difference representing the effectof the agent in opening up the structure for delamination and latticeexpansion.

EXAMPLE 1

Ten (10) grams of a South African vermiculite were combined in a shearmixer with 100 ml of 3M beta-alanine and the mixture agitated for atleast two (2) minutes. The material showed a lattice spacing of 12.65Angstrom Units (Å) before delaminating and a spacing of 32.1 Å aftertreatment.

EXAMPLE 2

The procedure of Example 1 was repeated, except that eight (8) grams ofvermiculite were combined with 100 ml. of 6M beta-alanine. The originallattice spacing of 12.65 Å was expanded to 35.3 Å, as shown by the lowangle, x-ray diffraction measurements.

EXAMPLE 3

The procedure of Example 1 was repeated, except that the beta-alaninewas replaced by 100 ml. of 3M 5-aminovaleric acid. Measurements showedthe lattice was expanded from the original 12.65 Å to 35.3 Å.

EXAMPLE 4

The procedure of Example 1 was repeated with the beta-alanine solutionreplaced by a 12.5% aqueous solution of lysine orotate, a primaryaminocarboxy acid having both an alkyl chain and a benzene ring in itsstructure. This produced a stable gel, and measurements showed theoriginal vermiculite lattice spacing expanded to 25.96 Å.

EXAMPLE 5

The procedure of Example 1 was repeated with the beta-alanine solutionreplaced by an aqueous solution of 3M glycine. This produced a stablegel in which the original 12.65 Å lattice spacing was expanded to 27.6Å.

EXAMPLE 6

The procedure of Example 1 was repeated with the beta-alanine solutionreplaced by an aqueous solution of 3M 6-aminocaproic acid. This produceda stable gel wherein the original lattice spacing was expanded to 31.6Å.

EXAMPLE 7

The procedure of Example 1 was repeated with the beta-alanine solutionreplaced by an aqueous solution of 1.5M 8-aminocaprylic acid. Thisproduced a stable gel in which the original 12.65 Å lattice spacing wasexpanded to 58.8 Å.

EXAMPLE 8

The procedure of Example 1 was repeated with the beta-alanine solutionbeing replaced by a 3M polyaminocarboxy acid solution, that is, asolution of a plurality of primary aminocarboxy acids. This produced astable gel wherein the original lattice spacing was expanded to about63.05 Å as shown by LAXRD measurements. As the gel stood in a beaker,polymerization could be seen to start along the wall of the beaker.

EXAMPLE 9

Ten (10) grams of a South African vermiculite were combined in a shearmixer with 100 ml. of an aqueous solution of 3M beta-alanine and one ml.of a quaternary ammonium silane available from the Dow-CorningCorporation, Midland, Mich. under the designation XZ-2-2300. The latticeof the vermiculite was shown by low angle, x-ray diffraction to havebeen expanded to 63 Å.

EXAMPLE 10

The procedure of Example 9 was repeated, except that the phyllosilicatematerial was phlogopite and 2 ml. of the quaternary ammonium silane wereadded with the 3M beta-alanine. Diffraction data showed a substantialportion of the phlogopite lattice spacing of 10 Å before treatment wasexpanded to 44.14 Å.

EXAMPLE 11

The procedure of Example 9 was repeated, except that the beta-alaninewas omitted and the vermiculite was sheared in an aqueous solution ofthe quaternary ammonium silane. Disintegration occurred but no gelformation. No lattice expansion was observed.

EXAMPLE 12

Eight (8) grams of natural hectorite were combined in a shear mixer with100 ml. of 3M beta-alanine and the mixture agitated for two minutes. Thepre-treatment lattice spacing of 13.28 Å in the hectorite was expandedto 17.69 Å.

EXAMPLE 13

Ten (10) grams of a fibrous phyllosilicate, sepiolite, were combined ina shear mixer with 100 ml. of the 3M polyamino acid solution of Example8, and the mixture agitated for two minutes. A stable gel resulted,although an expansion of the lattice was not observed in LAXRDmeasurements, possibly due to a different manner of expansion. A portionof the gel was poured out on a plate and dried in the ambientenvironment. The film formed was flexible and had a ductile, slightlyelastic nature.

EXAMPLE 14

Eight (8) grams of bentonite were combined with 100 ml. of a 6Mbeta-alanine aqueous solution in a shear mixer and agitated for twominutes. The lattice spacing of 12.62 Å was expanded to 18 Å.

EXAMPLE 15

The procedure of Example 14 was repeated, except that a phyllosilicate,known either as attapulgite clay or polygorskite, was used. The normallattice spacing of 10.57 Å was expanded to 19.6 Å.

EXAMPLE 16

One gram of a purified sodium montmorillonite, available from R. T.Vanderbilt under the designation Veegum T, was combined with 100 ml. of3M beta-alanine in a shear mixer and agitated a few minutes. The normallattice spacing of 11.5 Å was expanded to 13.6 Å. It was also ofinterest that the gel dried on a plate to a transparent film.

Examples 17, 18 and 19 are based on the use of syntheticphyllosilicates, that is, materials melted and crystallized in themanner described in U.S. Pat. No. 4,239,519 (Beall et al.). As formed,these synthetic materials are fluorinated and show no lattice spacing.However, when hydrolyzed, a spacing is observed, and that spacing isexpanded by acid treatment with an expanding agent as shown.

EXAMPLE 17

Ten (10) grams of synthetic hectorite were combined in a shear mixerwith 100 ml. of 6M beta-alanine and agitated for up to five minutes. Thelattice spacing in the hydrolyzed material was 12.4 Å and this wasexpanded to 18 Å.

EXAMPLE 18

Ten (10) grams of a synthetic strontium mica were combined with 100 ml.of an aqueous solution of 3M beta-alanine in a shear mixer and agitatedfor up to five minutes. The hydrolyzed lattice spacing of 15.5 Å wasexpanded to 21.5 Å.

EXAMPLE 19

The procedure of Example 18 was repeated employing ten (10) grams ofsynthetic sodium montmorillonite instead of strontium mica. Thehydrolyzed lattice spacing of 12.3 Å was expanded to 17.7 Å.

EXAMPLE 20

An experiment was designed to determine the potential for aminocarboxyacid recovery. A test gel was produced by dispersing ten (10) grams ofvermiculite in 100 ml. of 6N beta-alanine and pouring the mix into 2NHCl. This was followed by several separations in a centrifuge andwashing. Analysis of the vermiculite gel after four washes showed theamino acid content to be down to <0.031%.

For comparison a direct dialysis treatment was applied. After only three(3) changes of water, the amino acid content was down to less than oneppm. Thus, either technique may be used for acid recovery.

EXAMPLES 21-28

A study was made to determine the wide variety of polymerized materialsthat can be produced by additions to the gel produced by this invention.For this purpose five (5) liter lots of gel were produced by addingnatural vermiculite flakes to 3M beta-alanine to provide about 10%solids. The mix was subjected to a shear action in a blender for 5 to 10minutes to produce a stable gel. The gel was screened through a 270 meshscreen to remove all solids over 44 microns diameter, and thencentrifuged to a 30% solids' value. At this point aliquots were takenfrom a gel lot and a different addition made to each.

Several hundred separate material studies have been made. TABLE 1 setsforth representative examples in terms of the materials combined."Solids" represents vermiculite in the gel, "H₂ O" the water content,and "additive" the material and amount added.

                  TABLE 1                                                         ______________________________________                                        Ex.  Solids (gms.)                                                                            H.sub.2 O (ml.)                                                                         Additive                                            ______________________________________                                        21   4          60        10 ml. 10% 4-amino-                                                           benzoic/CH.sub.3 COOH.                              22   4          70        1 ml. 33% E-capro-                                                            lactam/2N HCl                                       23   4          70        1 ml. 50% E-capro-                                                            lactam/H.sub.2 SO.sub.4                             24   8          --        0.8 ml. 1M C.sub.3 H.sub.6 N.sub.6 /HCHO            25   4          --        2 ml. Nylon 6 in HCOOH                              26   8          --        0.1 gm. polyvinyl                                                             acetate/100 ml. methanol.                           27   8          100       5 ml. octylamine                                    28   4          60        10 ml. 33%                                                                    E-Caprolactam/2NHCl                                 ______________________________________                                    

Each of the mixtures shown in composition form in Table 1 was placed ona surface and heat treated in accordance with standard polymerizationpractice. The heat treating schedule for each example is shown in hoursand temperature in °C. in Table 2.

                  TABLE 2                                                         ______________________________________                                        Ex.  Time (hrs.)                                                                             Temp. (°C.)                                                                        Time (hrs.)                                                                           Temp. (°C.)                         ______________________________________                                        21   1         100         1       400                                        22   1         100         5       375                                        23   1         100         5       375                                        24   1         100          11/2   250                                        25   1         100          11/2   250                                        26   1         100          11/2   250                                        27   1         100         2       400                                        28   2         800         --      --                                         ______________________________________                                    

At completion of the indicated heat treatments, the polymerized productwas a hard solid having a visual appearance as shown in Table 3.

                  TABLE 3                                                         ______________________________________                                        Ex.         Appearance                                                        ______________________________________                                        21          medium grey, smooth, crystals visible                             22          light grey, very smooth                                           23          grey-brown, dull surface                                          24          grey-beige, rough surface                                         25          light grey, smooth surface                                        26          light grey, blistered surface                                     27          smooth, grey brown, some blisters                                 28          light beige brown, rough                                          ______________________________________                                    

EXAMPLES 29-34

Gel samples taken from the five liter lots described above in Examples21-28 were substantially diluted to provide gels containing 4, 6 or 8parts solids. Various additives were then incorporated into the gelsamples to intercalate with the silicate layers separated by the acid.Each resulting mixture was poured onto a flat surface and subjected to apolymerizing thermal treatment. This produced a film which was strippedfrom the surface for a tensile strength measurement in psi.

Table 4 shows the sample number, gel solids in parts/hundred, and theintercalated additive. Table 5 shows the polymerization schedule inhours and temperature in °C.

Table 6 shows the resulting film thickness (Thick) in inches and tensilestress (TS) in psi.

                  TABLE 4                                                         ______________________________________                                        Sample  Gel Solids    Additive                                                ______________________________________                                        29      4             5 ml. 0.1 M K.sub.2 Cr.sub.2 O.sub.7.                   30      4             5 ml. 0.1 M (NH.sub.4).sub.2 HPO.sub.4                  31      4             1 ml. 2M HCl                                            32      4             5 ml. 0.1 M (NH.sub.4).sub.2 HPO.sub.4                  33      8             100 ml. H.sub.2 O                                       34      8             --                                                      ______________________________________                                    

                  TABLE 5                                                         ______________________________________                                        Sample     1st heat       2nd heat                                            ______________________________________                                        29         1 hr. at 100° C.                                                                      1 hr. at 250° C.                             30         1 hr. at 100° C.                                                                      1 hr. at 400° C.                             31         1 hr. at 100° C.                                                                      1 hr. at 250° C.                             32         4 hrs. at 600° C.                                                                     --                                                  33         1 hr. at 100° C.                                                                      1 hr. at 250° C.                             34         1 hr. at 100° C.                                                                      1/2 hr. at 400° C.                           ______________________________________                                    

                  TABLE 6                                                         ______________________________________                                        Sample        Thick (in.)                                                                             TS (psi)                                              ______________________________________                                        29            0.006     6247                                                  30            0.005     6124                                                  31            0.004     5732                                                  32            0.004     5705                                                  33            0.006     5042                                                  34            0.008     6205                                                  ______________________________________                                    

EXAMPLES 35-40

In order to illustrate the synergistic effect between the expandablephyllosilicates and the primary aminocarboxy acids, a series ofexperiments was performed using a well known filler, calcium carbonate(CaCO₃). In one set of test samples, ten grams of CaCO₃ were added to 70milliliters of distilled water to form each sample. In the other set,ten grams of CaCO₃ were added to 70 milliliters of 0.1M beta-alanine.Samples were then dried at 25° C. (ambient); heated to 250° C. in airfor one hour; heated to 400° C. in air for one hour. Infra-redpolymerization measurements showed a set of peaks characteristic ofbeta-alanine when the beta-alanine sample dried at 25° C. was examined.Otherwise, all samples showed identical readings that indicated completeremoval of beta-alanine by heating.

For comparative purposes, infra-red polymerization studies were made onthe heat treated products of Examples 33 and 34 above. In thesematerials, the sole polymerizing material was residual beta-alanine. Thetraces were produced with a Perkin Elmer 1800 computer enhanced,infra-red spectrophotometer and are shown in FIG. 1 of the drawing.

The infra-red measurements, as well as observed properties and chemicalanalyses, demonstrate retention of the functional organic compound. Themeasurements made on the Example 33 material after a 250° C. heattreatment are shown in a curve designated "250° C." in FIG. 1. Belowthat, but essentially identical in shape, is a curve based on data fromthe Example 34 material after a 400° C. heat treatment and designated"400° C.". The peaks at 1656 and 1521 wave numbers, respectivelydesignated as Amide I and Amide II, and the N-H bend at the 1430 wavenumber, signify retention of the organic.

EXAMPLES 41-45

A series of gels was prepared and treated in accordance with theprocedures described for Examples 21-28. In each member of the series,the secondary additive was terephthalic acid with or withoutphenylenediamine. The basic gel was vermiculite dispersed in abeta-alanine solution, the solids' content being eight grams perhundred.

Table 7 lists the amount of secondary additive(s) in each composition:

                  TABLE 7                                                         ______________________________________                                                 Terephthalic        Phenylenediamine                                 Sample   acid added          added                                            ______________________________________                                        41       10 ml. of 5% solution                                                                             3 ml. of 10% solution                            42       10 ml. of 5% solution                                                                             1 ml. of 10% solution                            43       10 ml. of 5% solution                                                                             3 ml. of 10% solution                            44       1 ml. of 5% solution                                                                              --                                               45       5 ml. of 5% solution                                                                              5 ml. of 10% solution                            ______________________________________                                    

Each sample was then treated in a different manner to produce a solidbody. Example 42 was dried at 25° C. Examples 41 and 45 were thermallypolymerized by heating one hour at 100° C. followed by one hour at 400°C. Examples 43 and 44 were given the same thermal cycle, except that thesecond hour was at 250° C., rather than 400° C., in each case.

The bodies thus produced were tested to determine Young's modulus andtensile strength, and were chemically analyzed for carbon and nitrogencontents. The data determined are set forth in Table 8. Young's modulus(Mod.) is the value given multiplied by 10⁶ psi, tensile strength (T.S.)is in psi, and carbon (C) and nitrogen (N) are in percent by weight.

                  TABLE 8                                                         ______________________________________                                        Sample Mod. (×10.sup.6 psi)                                                                  T.S. (psi)                                                                              C (%)  N (%)                                   ______________________________________                                        41     5.66          10,144    4.68   1.16                                    42     6.82          5,430     5.42   1.70                                    43     7.85          9,464     5.10   1.55                                    44     6.88          6,760     2.42   0.75                                    45     6.45          9,384     4.34   1.24                                    ______________________________________                                    

EXAMPLES 46-49

A further series of gels was prepared employing autoclave-synthesizedlithium hectorites available from Laporte Industries Limited under thedesignations Laponite 825 and Laponite 127. Each gel was prepared byplacing ten grams of the phyllosilicate in 100 ml. of a 0.1M solution ofa primary aminocarboxy acid and agitating for a few minutes.

Table 9 shows, by the supplier's number, the phyllosilicate employed.The aminocarboxy acid employed is indicated by name:

                  TABLE 9                                                         ______________________________________                                        Example  Phyllosilicate Acid                                                  ______________________________________                                        46       825            beta-alanine                                          47       127            beta-alanine (0.3 M)                                  48       127            4-aminobutyric                                        49       127            glycine                                               ______________________________________                                    

A sample of each gel was poured onto a flat surface and dried at ambienttemperature, except for Example 48 which was dried at 80° C. under avacuum of 29" mercury. A second sample of each was spread onto a flatplate and heat treated under vacuum of 29" mercury. Examples 46 and 47were heated at 200° C. for four (4) hours, while Examples 48 and 49 wereheated at 200° C. for two (2) hours. In each instance, the solid filmproduct was transparent. This indicates the synthetic material isdispersed in very finely divided form in the film.

The phyllosilicates showed carbon (C) and nitrogen (N) contents on theorder of 0.1% or less as received. The contents of C and N, in weightpercent, as shown by analysis, are detailed in Table 10.

                  TABLE 10                                                        ______________________________________                                        Example  Treatment       C (%)   N (%)                                        ______________________________________                                        46       dried           10.7    4.3                                          47       dried           9.5     3.7                                          48       80° C.   4.6     1.3                                          49       dried           2.7     1.5                                          46       4 hr. at 200° C.                                                                       12.1    4.4                                          47       4 hr. at 200° C.                                                                       3.5     1.1                                          48       2 hr. at 200° C.                                                                       4.8     1.3                                          49       2 hr. at 200° C.                                                                       3.3     1.7                                          ______________________________________                                    

The analyses show both sustained retention of organic in the polymerizedproduct and an overwhelming amount of inorganic in a transparent film.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graphical illustration of infra-red measurements aspreviously described. The curves are plotted from infra-redspectrophotometer data and run from left to right. The vertical axisindicates degree of action and the horizontal axis indicates wavenumber.

FIGS. 2, 3 and 4 are scanning electron micrographs obtained with a Model1400 D scanning electron microscope supplied by Advanced Metals ResearchCorp. (AMR). The FIGURES show, respectively, (2) a vermiculite samplebefore treatment, (3) a polymerized sample of a vermiculite gel, and (4)an expanded sepiolite material as disclosed in Example 13.

FIG. 2 shows a scanning electron micrograph taken at 10,000Xmagnification of a polished vermiculite material as it was received fromthe supplier. The flaky, layered appearance is typical.

The material shown in FIG. 2 was then treated as disclosed in Example 8.The resulting gel was then polymerized by heating at 400° C. for onehour. A sample of the polymerized gel was then polished and a 10,000Xmagnification, scanning electron micrograph taken. This is shown in FIG.3 which illustrates the tight structure achieved by reconstitution ofthe vermiculite.

By way of contrast, FIG. 4 shows a 10,000X magnification, scanningelectron micrograph of a sepiolite gel prepared in accordance withExample 13. The characteristic chain or fibrous structure of sepioliteis apparent. It is evident that interesting characteristics can resultif phyllosilicates such as vermiculite and sepiolite are mixed by jointgel formation and then polymerized or otherwise reconstituted.

EXAMPLE 50

The procedure described in Example 1 was repeated with the beta-alaninesolution being replaced with an 11% aqueous solution of N-glycylglycine,a simple dipeptide having (--NHCO--) peptide linkages. A stable gel wasproduced in which the original lattice spacing of the vermiculite hadbeen expanded to 67 Å.

EXAMPLES 51-54

In this set of examples Nos. 51 and 52 comprised control samples; thatis, they consisted of South African vermiculite samples to which noexpanding agent was added. They were, however, subjected to a severeshearing force in a vibramill marketed by Tema, Inc., Cincinnati, Ohio,under the designation Siebtechik Type SM-6, VM. Thus, Example 51 wasmilled for one hour and Example 52 for 12 hours.

Example 52 comprised a sample consisting of 10% by weight drybeta-alanine, 90% by weight South African vermiculite. Example 53 wasvibramilled for one hour.

Example 54 provides a comparison with Example 53. Hence, Example 54comprised a sample consisting of South African vermiculite combined witha 10% aqueous solution of beta-alanine. Example 54 was vibramilled forone hour followed by milling for 10 minutes in a Kady mill, a relativelylow energy shear mixer marketed by Kinetic Dispersion Corporation,Scarborough, Me.

The average particle size (in microns) of each of the five samples wasmeasured and is reported in Table 11 in terms of the size of at leastone-half of the sample particles. Lattice values of the treated crystalswere measured again, utilizing low angle x-ray diffractometry, and arerecited in Table 11 in terms of Å.

                  TABLE 11                                                        ______________________________________                                        Example      Particle Size                                                                            Lattice Value                                         ______________________________________                                        51           39         14.6                                                  52           22         14.6                                                  53            8         21.0                                                  54             6.2      21.5                                                  ______________________________________                                    

A comparison of Examples 53 and 54 clearly indicates that the use of adry expanding agent can be equally effective in delaminating thephyllosilicate and expanding the lattice thereof. It is also apparentfrom Examples 51 and 52 that the use of high energy shearing actionalone is ineffective; an expanding agent must be present.

EXAMPLE 55

A sample consisting of 40 grams of South African vermiculite and 16grams of dry beta-alanine was charged into a Waring blender and mixedtogether therein for five minutes. Somewhat more than one-half of thevermiculite exhibited a lattice value in the neighborhood of 20 Å. Thus,even the low energy shearing action of a food blender can be effectivein delaminating the phyllosilicate and expanding the lattice thereof.Higher energy shearing action, however, appears to increase the rate ofdelamination.

I claim:
 1. An article of manufacture composed of a gel in dried andpolymerized form consisting essentially of at least one delaminatedhydrated or hydratable phyllosilicate combined with a lattice expandingagent selected from the group consisting of a primary aminocarboxy acid,lysine orotate, and glycylglycine, at least a portion of said latticeexpanding agent being intercalated in the lattice of saidphyllosilicate.
 2. A molded article of manufacture in accordance withclaim
 1. 3. A film in accordance with claim
 1. 4. An article ofmanufacture in accordance with claim 1 wherein the phyllosilicateconstituent is selected from the group consisting of vermiculite,sepiolite, sodium montmorillonite, and synthetic hectorite.
 5. Anarticle of manufacture in accordance with claim 1 consisting essentiallyof a phyllosilicate component and a polymerized primary aminocarboxyacid constituent.
 6. An article of manufacture in accordance with claim1 wherein said phyllosilicate is selected from the group consisting of amixture of natural phyllosilicates, a mixture of syntheticphyllosilicates, and a mixture of natural and synthetic phyllosilicates.7. An article of manufacture in accordance with claim 1 wherein said gelcontains an additive of a polymerizable material or agent selected fromthe group consisting of an organic compound, an inorganic compound, andmixtures of an organic and an inorganic compound, at least a portion ofwhich is present in the interlayer of said phyllosilicate.
 8. An articleof manufacture in accordance with claim 7 wherein said organic compoundis selected from the group consisting of melamine, guanidine, amides,tertiary and quaternary amines, silanols, caprolactams, epoxides,phenolics, polyesters, polyvinyls, acrylates, methacrylates, phthalates,acrylamides, polysulfones, stearates, citrates, acetates, and cyanates.9. An article of manufacture in accordance with claim 8 wherein saidorganic compound is selected from the group consisting of4-aminobenzoic/CH₃ COOH, E-caprolactam, polyvinyl acetate, octylamine,polyethlene terephthalate, and terephthalic acid+phenylenediamine. 10.An article of manufacture in accordance with claim 7 wherein saidinorganic compound is selected from the group consisting of nitrates,carbonates, chromates, sulfates, borates, halides, acid phosphates, andbasic phosphates.
 11. An article of manufacture in accordance with claim10 wherein said inorganic compound is selected from the group of K₂ Cr₂O₇, (NH₄)₂ HPO₄, and a silver compound.